Monday, July 23, 2018

Woodland musings: If a tree falls?

By Beth Sullivan
Each night I try to get out for a short walk in the woods. The Woodlot Sanctuary is almost in my backyard, so it is becoming home turf and I am enjoying the feeling of getting to know it. While it is a bit too dense ( and hot and buggy) to go too far off trail and into the wetter areas now, the trail loops offer something new to see each time I walk.
On this recent evening I was startled to see an obstruction on the trail where there had not been one the evening before. I was so sad to see that my favorite huge, old snag of a tree had fallen. This tree had been dead for a long time: its crown snapped off in one of the hurricanes in the 1980’s (Gloria or Bob). Over the years I have seen numerous woodpeckers working the tree, and recently, Pileated. Owls had nested in the broken top. Squirrels and raccoons made use of the hollow trunk. But what took it down, finally, was carpenter ants. These are the big, robust, black ants we dread to see in our homes and woodwork.
A surprise to see the old tree down on teh trail.

Bark beetles leave their trails on the old smooth wood.

Ant social structure

These colonial insects will inhabit a tree for decades, usually starting in live ones. Burrowing, tunneling, chewing safely deep inside the tree. Protected from weather extremes, they really don’t need to hibernate but may choose to retreat lower into the trunk or roots. In most colonies, the division of labor has created a system that assures there has been plenty of food stored within the many chambers. Other chambers are holding the queen and her eggs; others are nursery chambers where workers rear the young. It is an amazingly intricate and effective social system. However, ultimately, their own work is their undoing, and the tree falls. It has been discovered that carpenter ant colonies prefer their homes to be vertical. Once the tree is horizontal, they will abandon it and move elsewhere. On this evening, I examined the base and the trunk, and there wasn’t an ant to be seen.
This big old tree is not done with its usefulness yet. Mushrooms and other fungi will continue the decomposition process. Other insects and invertebrates will move in to further utilize the wood and the chambers. These will attract other woodpeckers which do not care if the tree is horizontal. Under the moist rotten wood, salamanders and worms will find homes. If the log could be lifted in a few seasons, there will surely be tunnels made by small mammals.
Indian Pipes rely on decayed, organic material, and have already begun to sprout in the rotten wood.

Small mammals will tunnel under and into the trunk to find protection and storage for their stash of food. Photograph by Rick Newton.

Silent encounter

As I walked around the log, paying attention to the ground, I stopped quickly and came face to face, literally, with a lovely Barred Owl. I am sure this bird had been watching me already for several minutes as I circled the log and took photos. It was no more than ten feet from me and about 6 feet off the ground. We really looked at each other for what seemed to be a minute, but was less I am sure. As I tried to get my camera up slowly, it turned away, not alarmed, gave a look over its shoulder and silently flew off, not far and still in sight.
What a special encounter. I wondered if this big old tree had played a part in its life.
This log and its remains will be present in this spot for many more years, and I will keep checking it. We won’t move it off the trail. It is easy enough to walk around. And it will provide a spot to sit, and wonder: “If a tree falls in the woods, and no one is around, does it make any sound? “
The tree was hollowed by carpenter ants.
The honeycombed chambers the ants created are really quite pretty.

A moments glimps and blurred photo but a great memory of a curious Barred Owl.

Photographs by Beth Sullivan, unless otherwise indicated.

1 comment:

  1. Beth,
    A delightfully informative narrative. I've been all over WoodLot - it is very fine. So, I learn that flipping a rotting log out of a trail path is likely un-roofing a home for worms chipmunks, and salamanders. In any case, even the last chapter has much to contribute in the cycle of life.
    Thank You